Continuous Casting Device for Producing Slabs Made of Steel

ABSTRACT

A continuous casting device for producing slabs of steel having a mold and a roller apron downstream of the mold which has frameworks with bottom frames and top frames at which are provided guide rollers whose gap width is continuously adjustable by means of adjusting elements which connect the frames. Cylinders controlled by switching valves are provided as adjusting elements. The advantages of position-regulated cylinders as adjusting elements are made use of, but at a reduced cost. To this end, the valves are constructed as fast switching valves, or the valves are provided with a control enabling a fast switching process.

PRIORITY CLAIM

This is a U.S. national stage of application No. PCT/DE2008/000032,filed on Jan. 7, 2008, which claims Priority to the German ApplicationNo.: 10 2007006458.8, filed: Feb. 5, 2007, the contents of both beingincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is directed to a continuous casting device for producingslabs of steel having a mold and a roller apron downstream of the mold,which has frameworks with bottom frames and top frames at which areprovided guide rollers whose gap width is continuously adjustable byadjusting elements which connect the frames, wherein hydraulic cylinderscontrolled by switching valves are provided as adjusting elements.

The invention is directed further to a method for operation of thecontinuous casting device.

2. Prior Art

EP 980 295 B1 discloses a continuous casting device for producing slabsof steel having a mold and a roller apron downstream of the latter whichhas frameworks with bottom frames and top frames at which are providedguide rollers whose gap width is continuously adjustable by adjustingelements which connect the frames. Distance measuring devices andpressure transducers are provided for detecting the actuating force ofthe adjusting elements and the gap width of the guide rollers. Further,an oscillator is provided for exciting oscillation in the adjustingelements. In practice, the segments used for this purpose are known asCyberLink segments. Generally, the oscillation is described byspecifying many discrete reference points per oscillation period. Thereference points have a sinusoidal distribution, and the movement isenforced so as to be regulated with respect to position.

This device can be used to acquire certain information relevant to theprocess such as, for example, the position of the liquid crater tip.

The position-regulated adjusting units used for this purpose arerelatively expensive. Therefore, it has already been proposed to replacethem with cylinders controlled by switching valves.

This solution is inexpensive but has the drawback that the advantageousoscillation can no longer be carried out in the known manner.

SUMMARY OF THE INVENTION

An object of the invention is to provide a the continuous casting devicesuch that the advantages of position-regulated cylinders as adjustingelements can be made use of, but at reduced cost.

This object is met according to one embodiment of the invention eitherby constructing the valves as fast switching valves or by providing thevalves with a control unit enabling a fast switching process.

According to another embodiment, the valves have connections foroptional arrangement of pressure measuring cells.

It is further proposed that:

-   1. the top frame is set in oscillatory motion by a fast toggling of    the switching valves over a relatively short measurement time    period—of a few seconds—so that the path signals and force signals    are evaluated subsequently in a known manner; it is taken into    account that a triangular motion that is eroded or slurred by the    inertia of the system occurs instead of a sinusoidal motion such as    was previously known; this has no effect on the precision or    reliability of the evaluation;-   2. the valves are provided with connections for arranging pressure    measuring devices so that the latter can either be included with the    valves when leaving the supplier or the valves can easily be    retrofitted in case of an upgrade.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic description of the system according to oneembodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Studies of measurements recorded in existing CyberLink segments withswitching valves have shown that the deformation speeds that can beachieved when using slightly larger dies than are commonly used (1.8mm-2.0 mm instead of 1.3 mm-1.5 mm) lie above the natural strand shelldeformation rates according to the creep behavior of the cast materialsand in the same order of magnitude as in the original CyberLink segmentssuch that an evaluation is possible.

The motion occurring by means of this control is not necessarilysinusoidal is not critical for the methods of evaluation (hysteresis,phase response, bath level movement) to be taken into consideration.

The fact that the mean cylinder position is possibly not held constantduring the measurement is accommodated by a measurement duration whichis as short as possible.

Overload monitoring is made possible by the optional use of pressuremeasuring cells.

Even without the use of pressure measuring cells, the proposed procedureshows a way to implement the “auxiliary CyberLink functions” when thecasting level signal is correlated with the top frame oscillationinstead of evaluating hysteresis or phase displacement.

In addition, the use of (electronic) devices is advantageous foraccelerating the switching processes.

Further, the installation of ventilators for improving convective heatremoval in the area of the valves can also be advantageous.

According to one embodiment of the invention as shown schematically inFIG. 1, the device for continuous casting configured for producing slabsof steel includes a mold, a roller apron arranged downstream of themold, the roller apron including a framework of at least one bottomframe and at least one top frame. A plurality of guide rollers arearranged in at least one of the at least one bottom frame and at leastone top frame. At least one cylinder is configured as an adjustingelement that connects the at least one bottom frame and at least one topframe, the at least one adjusting element configured to continuouslyadjust a gap width between the at least one bottom frame and at leastone top frame. A fast switching valve configured to control the at leastone cylinder is configured as an adjusting element. In one embodiment, agap width of the plural guide rollers is continuously adjustable. Atleast heat sink is configured for convective heat removal from the fastswitching valve.

Thus, while there have shown and described and pointed out fundamentalnovel features of the invention as applied to a preferred embodimentthereof, it will be understood that various omissions and substitutionsand changes in the form and details of the devices illustrated, and intheir operation, may be made by those skilled in the art withoutdeparting from the spirit of the invention. For example, it is expresslyintended that all combinations of those elements and/or method stepswhich perform substantially the same function in substantially the sameway to achieve the same results are within the scope of the invention.Moreover, it should be recognized that structures and/or elements and/ormethod steps shown and/or described in connection with any disclosedform or embodiment of the invention may be incorporated in any otherdisclosed or described or suggested form or embodiment as a generalmatter of design choice. It is the intention, therefore, to be limitedonly as indicated by the scope of the claims appended hereto.

1.-6. (canceled)
 7. A continuous casting device configured for producingslabs of steel comprising: a mold; a roller apron arranged downstream ofthe mold, the roller apron comprising a framework of at least one bottomframe and at least one top frame; a plurality of guide rollers arrangedin at least one of the at least one bottom frame and at least one topframe; at least one cylinder configured as an adjusting element thatconnects the at least one bottom frame and at least one top frame, theat least one adjusting element configured to continuously adjust a gapwidth between the at least one bottom frame and at least one top frame;and a fast switching valve configured to control the at least onecylinder configured as an adjusting element.
 8. A continuous castingdevice for producing slabs of steel comprising: a mold; a roller apronarranged downstream of the mold, the roller apron comprising a frameworkof at least one bottom frame and at least one top frame; a plurality ofguide rollers whose gap width is continuously adjustable; a pluralitycylinders configured as adjusting elements connect the at least onebottom frame and at least one top frame; a plurality of switching valvesconfigured to control respective ones of the plural cylinders; and acontrol configured to control the plural switching valves enabling afast switching process.
 9. The continuous casting device according toclaim 7, wherein the fast switching valve has a connection configuredfor attaching at least one pressure measuring cell.
 10. The continuouscasting device according to claim 7, wherein at least one unitconfigured for convective heat removal is associated with the fastswitching valve.
 11. A method for the operation of a continuous castingdevice, the continuous casting device comprising: a mold; a roller apronarranged downstream of the mold, the roller apron comprising a frameworkof at least one bottom frame and at least one top frame; a plurality ofguide rollers whose gap width is continuously adjustable; a pluralitycylinders configured as adjusting elements connect the at least onebottom frame and at least one top frame; a plurality of valvesconfigured to control respective ones of the plural cylinders; and acontrol configured to control the plural valves, the method comprising:oscillating the top frame using a triangular signal.
 12. The method forthe operation of a continuous casting device according to claim 11,wherein a measuring time for the oscillating of the top frame is asshort as possible.
 13. The continuous casting device according to claim8, wherein at least one of the plural switching valves has a connectionconfigured for attaching at least one pressure measuring cell.
 14. Thecontinuous casting device according to claim 8, wherein at least oneunit configured for convective heat removal is associated with at leastone of the plural switching valves.
 15. The method for the operation ofa continuous casting device according to claims 11, wherein thetriangular signal is eroded.
 16. The continuous casting device accordingto claim 10, wherein the at least one unit configured for convectiveheat removal is a ventilator.
 17. The continuous casting deviceaccording to claim 14, wherein the at least one unit configured forconvective heat removal is a ventilator.
 18. The continuous castingdevice according to claim 7, further comprising dies wherein the diesare about 1.8 mm to about 2 mm.
 19. The continuous casting deviceaccording to claim 8, further comprising dies wherein the dies are about1.8 mm to about 2 mm.
 20. The continuous casting device according toclaim 8, wherein the control is configured to oscillate the top frameusing a triangular signal.